/**
 * {}
 * @author yutent<yutent.io@gmail.com>
 * @date 2023/10/27 12:14:05
 */

import { EventEmitter } from 'node:events'
import { querystring } from './helper.js'

export class UrlencodedParser extends EventEmitter {
  #buf = Buffer.from('')
  #byteLen = 0

  initLength(length) {
    this.#byteLen = length
  }

  write(buffer) {
    this.#buf = Buffer.concat([this.#buf, buffer])
  }

  end() {
    if (this.#buf.length === this.#byteLen) {
      let data = this.#buf.toString()
      let fields = querystring(data)

      this.#buf = null

      this.emit('field', fields)
      this.emit('end')
      this.#buf = null
    } else {
      this.emit(
        'error',
        new Error(
          `The uploaded data is incomplete. Expected ${
            this.#byteLen
          }, Received ${this.#buf.length} .`
        )
      )
    }
  }
}